Supersensitization of photographic silver halide emulsions



April 19, 1960 J. c. Mol-ALL ET AL 2,933,390

SUPERSENSITIZATION OF' PHOTOGRAPHIC SILVER HALIDE EMULSIONS Filed OCT.. l2, 1955 A www ||l| im |11 wml 300, 400 500 600 ZOU A=3,5 -D/ETHYLT/-l/AD/CARBOCm/V/NE IUD/0E W/Z'H 4,4 -B/Sf- B 30|0||| mwmm lm im Mlm Fig. 3

C mu WTITTNIHH |||||l| 30,0 400 500 600 700 JOHN C. Mc FALL PAUL CROOKSHA/VK IN V EN TORS BY Zh.

(WM 7l. ea

ATTORNEYS v phenylene, naphthylene, etc.) and like groups.

United States Patent O sUPERsENsrrIzATIoN oF PHoroGRAPHrC SILVER HALIDE EMULsroNs John C. McFall and Paul R. Crookshank, Rochester,

N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Application October 12, 1955, Serial N 540,001 12 Claims. (ci. 96-100) This invention relates to photographic silver halide emulsions containing thiadicarbocyanine dyes, and as supersensitizers therefor, bis-triazinylaminostilbene compounds.

It is `known in the art of making photographic emulsions that certain dyes of the cyanine class alter theV sensitivity of photographic emulsions of the gelatine-silverhalide kind, when the dyes are incorporated in the emulsions. It is also'known that the sensitization produced by a given dye varies somewhat with the type of emulsion in which the dye is incorporated. Furthermore, the sensitization of a given emulsion by a given dye may be altered by varying the conditions in the emulsion. For example, the sensitization may be increased by increasing the silver ion concentration or decreasing the hydrogen io'n concentration (i.e., increasing the alkalinity) or both. Thus, sensitization canbe increased by bathing plates, coated with a spectrally sensitized emulsion, in water or in aqueous solutions of ammonia.` Such a process of altering the sensitivity of a sensitized emulsion by increasing the silver ion concentration and/or by decreasing the hydrogen io'n concentration `is commonly called hypersensitization Hypersensitized emulsions have generally poor keeping qualities. Y

n We have now found another means of altering the sensitivity in emulsions containing thiadicarbocyanine dyes. Since the conditions in the emulsion, i.e., the hydrogen ion and/or the silver ion concentration undergo little or no change in our method, we shall designate our method as a kind of supersensitization.

yIt is, therefore, an object of our invention to provide photographic emulsio'ns containing thiadicarbocyanine dyes and, as supersensitizers therefor, bis-triazinylaminostilbene compounds. Another object is to provide a process for preparing these supersensitized emulsions. Still another object is to provide photographic emulsions containing thiadicarbocyanine dyes and bis-triazinylaminostilbene compounds which are especially useful in color photography. Other objects will become apparent from a consideration of the following description and examples.

By thiadicarbocyanine dyes We mean dicarbocyanine dyes which contain two benzothiazole nuclei. These dyes can be unsubstituted on the carbocyclic rings, or on the polymethine chain, or they can be so substituted by alkyl groups (such as methyl, ethyl, etc.) alkoxyl groups (such as methoxyl, ethoXyl, etc.), aryloXyl groups `(such as phenoxyl, chlorophenoxyl, etc.), arylene groups (e.g.,

Particularly useful dyes comprise those represented by the following general formula:

. t wherein R and R1 each represents an alkyl group (such as methyl, ethyl, hydroxyethyl, carboxyrnetyl, -carboxyethyl, carbomethoxymethyl, carbethcXymethyI, etc. X represents an acid radical (such as chloride, bromide,

. 2,933,390 Ice -Patented PY- 19 196-0 2 iodide, perchlorate, thiocyanate, p-toluene-sulfonate, benzenesulfonate, methylsulfate, ethylsulfate, etc.), and Z and Z1 each represents the non-metallicV atoms necessary to complete a heterocyclic nucleus fof `the benzothiazole series (e.g., benzo'thiazole, 4-chlor`obenz'othiazole, 5-chlorobenzothiazole, 6-chlorobenzothiazole, 7-chlorobenzothiazole, 4methylbenzothiazole,y 5-methylbenzothiazole, 6-methylbenzothiazole,` 5-bromobenzothiazole, -bromobenzothiazole, 4-phenylbenzothiazole, 5phenylbenzothiazole, d 4methoxybcnzothiazole, 5-methoxybenzothiazole, G-methoxybenzothiazole, -iodobenzothiazole, 5-iodo'benzothiazole, 4ethoxybenzothiazole, d S-ethoxybenzothiazole, 5,6-dimethoxybenzothiazole, 5,6-doxymethylenebenzothiazole, S-hydroxybenzothiazole, -hydroxybenzothiazole, etc.

The bis-triazinylaminostilbene compounds useful in practicing our invention have been previously employed in the art as fluorescent agents and as bleaching (optical) agents, and hence are widely known substances. Especiallyuseful compounds of this class comprise those compounds represented by the following general formula:

wherein R6, R7, R2, and R3 each represents a hydrogen atom, or a substitutent group, such `as hydroxyl, aryloxyl (e.g., phenoxylLo-toloxyl, p-sulfophenoxyl, etc.), alkoxyl (e.g., methoxyl, ethoxyl, etc,), a halogen atom (e.g., chlorine,'bromine, etc.), a heterocyclic radical (e`.g., morpholinyl, piperidyl, etc.), an alkylthio group (c g., methylthio, ethylthio, etc.),` an arylthio` group (e.g., phenylthio, tolylthio, etc.), a heterocyclylthio group (e.g., berk zothiazylthio, etc.),V `an ,amino group, Van alkylamino group (e.g.methylamino', ethylarnino, propylamino, dimethylamino, diethylamino,` dodecylamino, cyclahexylamino, -hydroxyethylamino, di--hydroxyethylamino, -sulfoethylamino, etc.), an arylamino groupY (eg, anilino, o, m-, and p-sulfoanilinofog m, and p-chlo'roanilino, o, m-, and p-anisylamino, o, m, and p-toludino, o, m, and p-carboxyanilino, hydroxyanilino, sulfonaphthylamino, o, rn, and p-aminoanilino, p-acetarnidoanilino,` etc.), etc., and R4 and R5 each represents a hydrogen atom or a water-solubilizing group, 'such assulfo, carboxyl, etc. (as well as alkali metal or amine salts of such groups). Many of the compounds represented by Formula II above are known substances, and methods for preparing these compounds are well known. Listed below are representative compounds selected from those represented by Formula Il, although our invention is not limited in any sense to these particular compounds. While the structural formulas are includedfor only the rszt three compounds,rit is to be understood that the same numbering system is employed throughout the specification.

-sonH soin l,sous soin NH--CHICHz-OH Compounds of the above type which can advantageously be employed m practicing our invention have been described in one or more of the following representative patents:

agees@ NH-CHaCHz-OH 'Ihese products have been previously employed in the textile field, and are sold under such trade names as LeucophorY B, Calcoiiuor White MR, Tinopal (SP, WR, BV277, 2B, GS, NG), Blanco'f'or SC, Hiltamine (BSP, N, Sol., 6T6), and the like.

According to ourV nvention,.we incorporate one or more of the thiadicarbocyanine dyes represented by Formula I above with one or more s-triazinylaminostilbene compo'unds, such as those represented by Formula II above. Our invention is particularly directed to the ordinarily employed gelatiuo-silver-halide emulsions. However, our supersensitizing combinations can be employed in silver halide emulsions in which the carrier is other than gelatin, e.g., a resinuous substance or cellulosic materal which has no deteriorating eifect on the light-sensitive materials.- The thiadcarbocyanine dyes and s-triazinylaminostilbene compounds can be employed in various concentrations depending upon the eiects desired.

Ordinarily, the optimum or near optimum concentration of the thiadicarbocyanine `dyes which we employ in practicing our invention is of the order of from 0.010 to 0.30 g. per mol. of silver halide in the emulsion.

The's-triazinylaminostilbene compounds which we employ in our invention can advantageously be employed at a concentration of from about 0.03 to 10.0 g. permol. of silver halide in the emulsion. In generaLthe ratio of concentration of, thiadicarbocyanine dye to s-triazinylaminostilbene compound can vary, rather widely in our combinations,e.g., from 1:1V to 1:300 (by weight) in many cases.

The methods of incorporating sensitizing dyes in silver halide emulsions are well known to those skilled in the art. The s-triazinylaminostilbene compounds can be directly dispersed in the emulsions, or they can be dissolved in water (or an organic solvent, such as methanol, ethanol,'etc., where the water-solubilityis not sufficiently great) and added in the form of their solutions. While the thiadicarbocyanine dyes Ycan be directly dispersed in the emulsions, it is convenient to add the same in the form of solutions in appropriate solvents. Methanol, ethanol, pyridine, and'the like have proven satisfactory for manyjof the dyes of Formula I. Mixtures of solvents, e.g., pyridine diluted with methanol or acetone, can also be used. The thiadicarbocyanine dyes and s-triazinylaminostilbene compounds are dispersed in the finished emulsions' and should be uniformly distributed throughout the emulsions. The following procedure is satisfactory: Stock solutions of the thiadicarbocyanine dyes and stilbene compounds are prepared by dissolving the same in appropriate solvents as described above. Then, to the iiowable gelatino-silver-halide emulsion, the desired amounts of the stock solution of one of the dyes (or stilbene compounds) are slowly added, While stirring the emulsion. Stirring is continued until the dye is thoroughly incorporated in the emulsion. Then the desired amount of the stock solution of the stilbene compound (or dye, if stilbene compound has been added first) is slowly added to the emulsion, while stirring. fStirring is continued until the second solution is thoroughly incorporated. The supersensitized emulsion can then be coated out on a suitable support, such as glass, cellulose derivative ilm, resin film, or paper, to a suitable thickness and allowed to dry. The details of such coating methods are -well known to those skilled in the art. The foregoing procedures and proportions are to be regarded only as illustrative. Clearly, our invention is directed yto vany silver halide emulsion containing a combination of the aforesaid thiadicarbocyanine dyes and s-triazinylaminostilbene compounds whereby a supersentitizing effect is obtained.

The following examples will serve to illustrate further triazin-Z-ylamino]stilbene-2,2disulfonic acid. The sensitometric measurements are given in Example 3 of the above tab-le.

`In Figure 2, curve B represents the sensitivity of an ordinary gelatino-silver-bromiodide emulsion sensitized the manner of practicing our invention. with 3,3'di(hydroxyethyl)thiadicarbocyanine bromide In Table I below, to different portions of the same and 4,4bis[4-(4'sulfoanilino)--(-hydroxyethylamibatch of photographic. gelatino-silver-halide emulsion no)-s-triazin-Z-ylaminolstilbene2,2disulfonic acid. The were added (1) a thiadicarbocyanine dye, such as those sensitometric measurements are given in Example 4 of represented by Formula I above, and (2) a combination 10 the above table. `of the thiadicarbocyanine dye and a bis(s-triazin2 ln Figure 3, curve C represents the sensitivity of an `ylammo)stilbene (in neutral aqueous solution). Then ordinary gelatino-silver-bromiodide emulsion sensitized the emulsions were held at about 40 C. for a short time with 3ethyl3 methyl-8,10-o-phenylenethiadicarbocyaand coated on a support, chill set, and dried. After exnine iodide and 4,4'bis[4(4sulfoanilino)-d-(hydroxyposurethrough a Vit/ratten No. filter, i.e., a iilter which 15 ethylamino)-striazin-2-ylamino] stilbene-2 ,2disulfonic transmits substantially no light of wavelength shorter acid. The sensitometric measurements are given in Exthan about 580 mu, in an Eastman Type IB sensitometer, ample 5 in the above table. the film strips were processed for 3 minutes in a developer Our invention is primarily directed to the ordinarily having the following composition: employed gelatine-silver-halide developing-out emulsions,

g 20 e.g., gelatiiio-silver-chloride, chlorobromide, -chloroio- N methy1 p amin0pheno1Sula 1 i0 dide, chlorobromiodide, -bromide and -bromiodide de- Hydroquinone 8.0 veloping-out emulsions. Emulsions which form the latent Sodium Sul (esiccated) 90.0 image. mostly inside the silver halide grains, such as the Sodium Carbonate (monohydrate) 52.5 emulsions set forth in U.S.V Patent 2,456,956, dated De- Potassium bromide 5 0 25 cember 21, 1948, can also be employed in practicing our Water to ak 1 l`te Inventum' Y m e l r The emulsions prepared 1n accordance with our inven- Tlie speed (red), gamma and fog for each of the coattion can be coated in the usual manner on any suitable ings was then measured. The results are. recorded in support, eg., glass, cellulose nitrate lm, cellulose acetate Table -I. 'iilm, polyvinylacetalrresin film, paper or metal.

` TABLE I Red Light Exposure Example Senstizing Dye and Addenda (g./mo1. AgX) SO/E Gamma Fog Speed 1 i (a) 3,3diethylthiadicarboeyanine iodide (.075) 18 3.3 .17 (b) dye (a) (.075) plus Calcoiluor White MR* (.13) 32 1.9 .15 2 (c) 3,3di(-hydroxyethyl)tliiadicarbocyanine bromide 5) 16 4.1 .09 (d) dye (c) (.075) plus Calcoiluor White MR* (.13). 26 2. 6 10 3 {(e) dye (a) (.050) 4.6 0.9 .06 (f) dye (a).(.050) plus compound 4 (3.0)-.--- 13. 7 2. 7 .0G 4 {(0} dye (C) (.050).- 7.6l 2.4 .06 j (h) dye (c) (.050) plus eompound. (3.0) 14.4 3.0 .06 5, {(i) 3'ethyl-3411ethyl-8,10-o-pheny1enethiadicarbocyanineiodide (050)., no. sens. .05 (j) dye (i) (.050) plus compound 4 (3.0). 5- 6 1.6 .O5 6 {(0} dye (a) (.050) 2.8 0. 4s .ce (l) dye (a.) (.050) plus oaiconuor White MR* (3.0)..- 25. 5 2.3 .00 7 {(m) dye (c) (.050) 8.65 2.3 .06 (n) dye (c) (.050)p1us oaiconuor White MR* 14.7 2.4 .07 8 {(0} Adye (i) (.050) .5i 1.8 .0s (p) dye (i) (.050) plus Calcofluor White MR* (3.0) 2.8 1.8 .07

f Calcofluor White MR is a bis (s-triazin-Z-ylamino)stilbene-2,2'disulfonic acid (sodium salt).

In the above table, the coatings of Examples 1 and 2 were made from the same batch of gelatino-silver-chloro- 'bromide emulsion, the coatings of Examples 3, 4 and 5 were made from the same batch of gelatinosilverbromiodide emulsioin'the coatings of Example 6 were made from the same batch of gelatino-silver-bromiodide emulsion, and the coatings of Examples 7 and 8 were made from the same batch of gelatino-silver-bromiodide emulsion.

The accompanying drawing illustrates the supersensitizing effect obtained with three of our new combinations in gelatino-silver-bromiodide emulsions. Each figure of the drawing is a diagrammatic reproduction of one spectiogram. The sensitivity of the emulsion containing both the thiadcarbocyanine dye and the bis(st1iaZin-2 ylamino)stilbene `compound is represented by the solid curve. No curve for the emulsions containing the thiadicarbocyanine dyes alone has been shown, since these dyes sensitized too weakly to give satisfactory spectograms.

ln Figure l, curve A represents the sensitivity of an ordinary gelatine-silver-bromiodide emulsion sensitized with 3,3'-diethylthiadicarbocyanine iodide and 4,4bis[4 (4' sulfoanilino) 6 hydroxyethylamino) s Gir Photographic silver halide emulsions, such as those listed above, containing the supersensitizing combinations of our invention can also contain such addenda as chemical sensitizers, e.g., sulfur sensitizers (e.g., allyl thiocarbamide, thiourea, allylisothiocyanate, cystine, etc), various gold compounds (e.g., potassium chloroaurate, auric trichloride, etc.) (see U.S. Patents 2,540,085; 2,597,856 and 2,597,915), various palladium compounds, suchvas palladium chloride (U.S. 2,540,086), potassium chloro palladate (U.S. 2,598,079), etc., or mixtures of such sensitizers; antifoggants, such as ammonium chloroplatinate (U.S. 2,566,245), ammonium chloroplatinite (U.S.

^7 I Such silver halide emulsions can also contain thiazolidone or other ultraviolet absorbing compounds, such as those described in the copending application Serial No. 419,239, iledMarch 29, 1954, in the name of G.V W.

. 8 tino chlorobromide emulsion, and in certain coatings, (4) a thiazolidone ultraviolet absorbing compound, such as benzal 3 n cetyl 2 phenylimino-4-thiazolidone, in the amounts shown in the table and/ ora bis(striazin Sawdey, now U.S. Patent 2,739,888, issued March 27, 5 2-ylamino)stilbene compound, such as Leucophor B (a. 1956. While certain emulsion addenda, such'as certain bis(s-triazin2ylamino)stilbene-2,2disulfonic acid), in ultraviolet compounds, and certain color-forming comthe amounts shown in the table. In addition to this cyan pounds cause de-sensitization or un-sensitizing eects, it layer, the coatings had a magneta layer (green sensitive) has been found that the lnew combinations of our invencontaining an incorporated color-forming compound of tion largely overcome such effects. Typical color-formthe type shown in U.S. Patent 2,600,788 mentioned above ing compounds which can be so employed includethose and a yellow layer (blue sensitive) containing an incorin U.S. Patent 2,322,027 and the following: porated color-forming compound of the type shown in Mc- C 1 Crossen et al. U.S. application Ser. No. 476,159, led De OUP erf v cernber 20, 1,954, now abandoned. The coatings were (1) 1 1- hydroxy 2 l-(2,4ditert.amylphenoxy)-n- 15 then exposed and developed in the usual manner. The butyll-naphthamide (U.S. Patent 2,474,293) speed (log E, 0.6 above fog) and gamma (contrast) of the (2) 1 hydroxy 4-phenylazo-4-(ptert.butylphen0xy) cyan layer was measured in addition to the cyan, magental l 2naphthanilide (U.S. Patent 2,521,908) and yellow dye loss after 10 days exposure to radiation (3) 2-(2,4-di-tert.amylphenoxyacetamino) 4,6dchl0ro containing ultraviolet radiation. Prntout density for y 5methy1 phenol (Graham U.S. 'applicatlon Serial No. 20 the exposed coatings was also measured after l0 days. 285,544, now U.S. Patent 2,725,291) The results are given in the following table. While the (4) 2 (a-2,4ditert.amylphenoxyfn-butyrylammo)4,6 U.V. absorbingrcompound protected the cyan, magenta dichloro-S-methyl phenol and yellow dye layers against dye loss (fading), it'caused `(5) 64- {a{4[a(2,4-di-tert.amylphenoxy)butyramido]- a rather severeloss in speed. On the other'hand, the phenoxy}acetamido}f2,4dichloro-3-methyl phenol 25 stilbene compoundv more than restored this loss in speed (6) 2 [3'(2",4diamylphenoxy) acetamdOJ-benzwithout adversely affecting the stabilizing effect of the amido-4-chloro-5-methyl phenol U.V. compound.VA

TABLE 1I U.V. Com- Stilbene Red 10 Day Cyan Magenta Yellow Example pound, Comp., Log E Gamma Print-Out Dye Loss Dye Loss Dye Loss mg./sq.ft. mg./sq.ft. Speed Density (10days) (10days) (10days) 0 0 0.60 1.51 +.2a .32 .46 .56 157 0 0.25 m1 +.12 .27 .22 .28 157 5 0.78 1.58 +.07 .10 12 .25 157 15 0.82 1.45 +.05 .22 .18 .25 157 25 0. 89 1.54 +.05 .26 .18 .25 0 0 0. 5s 1.38 +.20 .24 .44 .72 Y 0 e5 0.09 1.31 12 .22 .35 .45 e5 0.94 1. 44 l +.04 .18 .22 .24 65 0. 01 1. 40 +.04 19 .25 .28 157 30 0.71 1, 46 01 .17 .22 10 Y 157 0 0.37 nn +.05 15 .34 .28 157 1 0. 79 1.41 +.05 .20 .15 .25 Y 157 2 0. 85 1.41 +.05 .12 15 .25 157 4 0.94 1.50 -1-.08 .18 .15 .30

- Leucophor B is a bis (s-triazin-zylamino)stilbeue2,2'disulfon.ic acid (sodium salt).

tert.amylphenoxyacetarnido)-benzamidol 5 pyraz *The following table and examples will'serve to illustrate the beneficial effects of our new supersensitizing Vcc'i'rnbinations when employed in multilayer photographic emulsion layersk containing incorporated color-forming compounds. In Table II below these beneficial efects are illustrated with respect to a multilayer color element having an outermost cyan layer (red sensitive) containing (1) a-c'oupler dispersion of a color-forming compound, such as coupler No. 5 above, (2) a red sensitizing dye, such as 3,3'-diethylthiadicarbocyanine iodide, (3) a gela- While separate emulsion batches were employed in Examples 9, 10 and 11 above, the same emulsion batches were employed for the coatings of a given example for purposes of comparison. The word nil as used in the table means too low to be significant, or not measurable.

The following examples will serve to illustrate further the beneicial effects of our new combinations in photographic silver halide emulsions.

Example 12 A washed gelatino-chlorobromide emulsion sensitized with .035 g./mol. of silver halide of 3,3di(hydroxy ethyl)thiadicarbocyanine bromide was coated both with and without the addition of 52 g./mol. of silver halide of a bis(s-triazin-Z-ylamino)stilbene-2,2disulfonic acid (Leucophor. B). Both coatings after exposure were developed in the usual manner to form a silver image. The coating containing the stilbene compound was 0.12 log E units higher in blue speed and 0.26 log E units higher in red speed than the coating which did not contain the stilbene compound.

Example 13 A washed gelatino-chlorobromide emulsion sensitized with .035 gJmol. of silver halide of 3,3di(hydroxy ethyl)thiadicarbocyanine bromide was coated both with and without the addition of 52 g./mol. of silver halide of a `bis(striazin2ylamino)stilbene-2,2f-disulfoncY acid `ner, then bleached to give a dye image.

9 (Leucophor B). Both coatings contained a dispersion of a dye coupler, such as coupler No. 9 above, and after exposure the coatings were developed in the usual man- The coating containing the stilbene compound was .05 log E units higher in blue speed and .1S log E units higher in red speed than the coating which did not contain the stilbene compound.

` Example 14 A washed gelatino-chlorobromide emulsion sensitized ethyl)thiadicarbocyanine bromide was coated both with and without the addition of g./ mol. of silver halide of a bis(s-triazin-Z-ylamino)stilbene2,2disulfonic acid (Leucophor B). Both coatings contained a dispersion of a dye coupler, such as coupler No. 9 above, and the coatings were developed in the usual manner, then bleached to give a dye image. The coating containing the stilbene compound was .16 log E units higher in blue speed and ".34 log E units higher in red speed than the coating which did not contain the stilbene compound.

Example 15 An unwashed gelatino-chlorobrornide emulsion sensi- Vtizedwith .039 g./mol. of silver halide of 3,3di(hyudroxyethyl)thiadicarbocyanine bromide was coated both with and without the addition of 26 g. of a bis(s-triazin2- ylamino)stilbene-2,2disulfonic acid (Leucophor B). Both coatings contained a dispersion of dye coupler, such as coupler No. 9 above, and after exposure were developed in the usual manner in a black and white developer, reexposed, and subjected to color development, bleaching -and xing to produce a dye image. The coating containing the stilbene compound was .37 log E units higher in red speed than that which did not contain the Astilbene compound.

Example 16 Vmean a compound of the following structure:

D-NH NH-Di wherein R4 and R5 each have the values given above, and D and D1 each represents a s-triazin-2-yl nucleus. The thiadicarbocyanine dyes of Formula I comprise a well known class of optical sensitizing dyes. Methods for making these dyes have been previously described in the prior art. See, for example, U.S. Patent 2,213,238, issued September 3, 1940; U.S. Patent 2,231,658, issued February ll, 1941; U.S. Patent 2,265,909, issued December 9, 1941; U.S. Patent 2,269,234, issued January 6, 1942; and British Patent 562,567, accepted July 6, 1944. Dye (i) in Table I was made as described,` in U.S. Patent 2,265,909 and was obtained as dark blue needles melting at 191-2" C. dec. Y

As mentioned above, many of the compounds represented by Formula II above have been described in the prior art. Examples of preparing such compounds are given in the copending application Serial No. 540,054,

tiled oneven date herewith in the names of B. Car-V roll, J. E. Jones and J. Spence.

In Table I above, no data for the emulsions containing the stilbene compound alone are given, since it has been found from numerous coatings that such compounds when used alone have little or no sensitometric eiect on the emulsions.

The compounds of Formula II also showed marked antistainng properties in many instances, and also antifoggant properties Vin certain instances, in addition to their supersensitizing and anti-unsensitizing effects. VWe have also found that compounds represented by Formula II above, wherein R2, R3, R6 and/or R7 represent a heterocyclylamino group (e.g., 2benzothiazylamino, 2- pyridylamino, etc.) can advantageously be employed in practicing our invention. `For the preparation of such compounds, see the process described in the copending application of Carroll, Jones and Spence Serial No. 540,- 052, tiled on even date herewith. p

The disulfonic acids of Formula II are generally employed in neutral aqueous solution as mentioned above,

i.e., the free acids are at least partially neutralized with wherein R and R1 each represents an alkyl group con'- taining from 1 to 4 carbon atoms, X represents an acid radical, and Z and Z1 each represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and at least one bis(striazin2 ylamino)stilbene compound selected from the class represented by the following general formula:

/N T N\ l ttt-N( WINNH CHzCH. /AH lL-R' Y IL ni, V

wherein R2, R3, R6 and R7 each represents. a member selected from the group consisting of a hydrogen atom, a hydroxyl group, an aryloxyl group, an alkoxyl group, a halogen atom, a heterocyclic radical, an alkylthio group, an arylthio group, and an amino group, and R4 and R5 each represents a member selected from the group consisting of a hydrogen atom and a sulfo group.

2. A photographic gelatine-silver-halide developing-out emulsion sensitized with a supersensitizing combination of at least one thiadicarbocyanine dye selected from the class represented by the following general formula:

wherein R and R1 each represents an alkyl group containing from 1 to 2 carbon atoms, and Z and Z1 each represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, andat least one bis(striaziue2ylamino)stilbene com- 'pound selected from the class represented by the following general formula:

SOaH SOaH wherein D and D1 each represents a s-triazin2-yl nucleus.

3. A photographic gelatino-silver-bromiodide developing-out emulsion sensitized with a supersensitizing combination of at least one thiadicarbocyanine dye selected from' the class represented by the following A'general formula:

` l/Z\\ i l l/Zb` R-l e--oH=Cnton=onorr=V I-Rl `Wherein R and R1 each represents an alkyl group containing from 1 to 2 carbon atoms, X'represents an acid radical, and Z and Z1 each represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and at least one bis(striazin2 ylamino) stilbene compound selected from the class represented by the following general formula:

SOgH SOaE wherein D and D1 each represents a s-triazin-Z-yl nucleus.

4. A photographic gelatino-silverchlorobromide developing-out emulsion sensitized with av supersensitizing combination ofV at least one thiadicarbocyanine dye selected from the class represented by the following general formula:

Wherein R and R1 each represents an alkyl group containing from 1 to 2 carbon atoms, X represents an acid radical, and Z 'and Z1 each Vrepresents the non-metallic .atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and at least one bis(striazin2 ylamino)stilbenecompound selected from the class represented by the following general formula:

soan sont wherein D and D1 each represents a s-triazin-Z-yl nucleus. 5. A photographic gelatine-silver-halide developing-out emulsion sensitized with a supersensitizing combination of a 3,3diethylthiadicarbocyanine salt and at least one bis(striazin2ylamino)stilbene compound selected from the class represented by the following general formula:

SOaH SOgH SosH wherein D and D1 each represents a s-triazin-Z-yl nucleus.v

j Y i7. photographic gelatino-slver-halide developing-out emulsion sensitized with a supersensitizing combination pound selected from the class represented by the following general formula:

| SOaH SOgE wherein D and D1 each represents a s-triazin-2-yl nucleus. '8. A photographic gelatino-silver-halide developing-out emulsion sensitized with a supersensitizing combination veloping agent to form a cyan dye image, (2) a th'iadicarbocyanine dye selected from the class represented by the following general formula:

/X\ /Zlg l wherein R and R1 each represents an alkyl group containing from 1 to 4 carbon atoms, X represents an acid radical, and Z and Z1 each represents the non-metallic atoms necessary to complete atheterocyclic nucleus of the 'benzothiazole series, and V(3) a bis(s"triazin2-V y1amir'1o)stilbene Ycompound selected from the class represented by the following general formula:

fr er wherein R2, R3, R8 and R7 each represents a member selected from the group consisting of amhydrogeu atom, a hydroxyl group, an aryloxyl group, an alkoxyl group, a halogen atom, a heterocyclic radical, an alkylthio group, an arylthio group, and an amino group, and R4 and R5 each represents a member selected from the group con# sisting of a hydrogen atom and a sulfo group.

12. A photographic silver halide developing-out emulsion capable of producing a dye image comprising a. gelatino-silver-halide developing-out emulsion containing L(l) adispersion of a phenol, color-forming compound capable of reacting with a primary aromatic amine developing agent to form a cyan dye image, (2) a thiadi-l carbocyanine dye selected from the class represented the following general formula:

wherein R and R1 each represents'an alkyl group contain;

13 Y ing from 1 to 4 carbon atoms, X represents an acid References Cited inthe file of this patent radical, and Z and Z1 each represents the non-metallic UNITED STATES PATENTS atoms necessary to complete a heterocyclic nucleus of the benzothiazole Series, and (3) a bis(striazin-2- 2,367,551 Yule Jal-1 16, 1945 Ylamllotilbene compound selected from me dass repre- 5 2,476,536 lgerseh my 19, 1949 sented by the fOllOWing general formula: 2,718,466 Wolfson Selm 20, 1955 FOREIGN PATENTS Y D-NH CH=CH N11-D, 675,656 Great Britain July 16, 1952 SOaH SOH 10 OTHER REFERENCES Mees: The Theory of the Photographic Process, wherein D and D1 each represents a s-triazin-Z-yl nucleus. Macmillan Co., N Y. (1954), page 365.

UNITED STATES PATENT OFFICE Certificate of Correction Patent No. 2,939,390 April 19, 1960 John C. McFall et al. It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should. read as corrected below.

Column 1, lines 65 to 68, FormulaJ (I) should appear as shown below instead of as in the patent:

/Z"` /zl column 2, lines 61 to 66, the upper right-hand portion of Formula (I) should appear as shown below instead of as 1n the patent:

column 3, line 45 compound (15), for 4,4-bi s reed -4,4bis-; column 10, line 72, after atoms, insert -X represents an acld rad1cal,-; column 12, lines 37 to 40, and lines 71 to 74, the formulaJ in each occurrence should appear as shown below instead of as in the patent:

fz" 'Zh` R-/:bGH=CH0H=CHCH=L`R1 Signed and sealed this 22nd day of November 1960.

[SML] Attest:

KARL H. AXLINE, Attestz'ng Ozfaer.

ROBERT C. WATSON, omnz'aaomr of Patents. 

11. A PHOTOGRAPHIC SILVER HALIDE DEVELOPING-OUT EMULSION CAPABLE OF PRODUCING A DYE IMAGE COMPRISING A GELATINO-SILVER-HALIDE DEVELOPING-OUT EMULSION CONTAINING (1) A DISPERSION OF A PHENOL, COLOR-FORMING COMPOUND CAPABLE OF REACTING WITH A PRIMARY AROMATIC AMINE DEVELOPING AGENT TO FORM A CYAN DYE IMAGE, (2) A THIADICARBOCYANINE DYE SELECTED FROM THE CLASS REPRESENTED BY THE FOLLOWING GENERAL FORMULA: 